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 Bayesian Learning


Modeling the Social Influence of COVID-19 via Personalized Propagation with Deep Learning

arXiv.org Artificial Intelligence

Social influence prediction has permeated many domains, including marketing, behavior prediction, recommendation systems, and more. However, traditional methods of predicting social influence not only require domain expertise,they also rely on extracting user features, which can be very tedious. Additionally, graph convolutional networks (GCNs), which deals with graph data in non-Euclidean space, are not directly applicable to Euclidean space. To overcome these problems, we extended DeepInf such that it can predict the social influence of COVID-19 via the transition probability of the page rank domain. Furthermore, our implementation gives rise to a deep learning-based personalized propagation algorithm, called DeepPP. The resulting algorithm combines the personalized propagation of a neural prediction model with the approximate personalized propagation of a neural prediction model from page rank analysis. Four social networks from different domains as well as two COVID-19 datasets were used to demonstrate the efficiency and effectiveness of the proposed algorithm. Compared to other baseline methods, DeepPP provides more accurate social influence predictions. Further, experiments demonstrate that DeepPP can be applied to real-world prediction data for COVID-19.


Debiasing Deep Chest X-Ray Classifiers using Intra- and Post-processing Methods

arXiv.org Artificial Intelligence

Deep neural networks for image-based screening and computer-aided diagnosis have achieved expert-level performance on various medical imaging modalities, including chest radiographs. Recently, several works have indicated that these state-of-the-art classifiers can be biased with respect to sensitive patient attributes, such as race or gender, leading to growing concerns about demographic disparities and discrimination resulting from algorithmic and model-based decision-making in healthcare. Fair machine learning has focused on mitigating such biases against disadvantaged or marginalised groups, mainly concentrating on tabular data or natural images. This work presents two novel intra-processing techniques based on fine-tuning and pruning an already-trained neural network. These methods are simple yet effective and can be readily applied post hoc in a setting where the protected attribute is unknown during the model development and test time. In addition, we compare several intra- and post-processing approaches applied to debiasing deep chest X-ray classifiers. To the best of our knowledge, this is one of the first efforts studying debiasing methods on chest radiographs. Our results suggest that the considered approaches successfully mitigate biases in fully connected and convolutional neural networks offering stable performance under various settings. The discussed methods can help achieve group fairness of deep medical image classifiers when deploying them in domains with different fairness considerations and constraints.


Geometric Methods for Sampling, Optimisation, Inference and Adaptive Agents

arXiv.org Artificial Intelligence

In this chapter, we identify fundamental geometric structures that underlie the problems of sampling, optimisation, inference and adaptive decision-making. Based on this identification, we derive algorithms that exploit these geometric structures to solve these problems efficiently. We show that a wide range of geometric theories emerge naturally in these fields, ranging from measure-preserving processes, information divergences, Poisson geometry, and geometric integration. Specifically, we explain how (i) leveraging the symplectic geometry of Hamiltonian systems enable us to construct (accelerated) sampling and optimisation methods, (ii) the theory of Hilbertian subspaces and Stein operators provides a general methodology to obtain robust estimators, (iii) preserving the information geometry of decision-making yields adaptive agents that perform active inference. Throughout, we emphasise the rich connections between these fields; e.g., inference draws on sampling and optimisation, and adaptive decision-making assesses decisions by inferring their counterfactual consequences. Our exposition provides a conceptual overview of underlying ideas, rather than a technical discussion, which can be found in the references herein.


Machine Learning to Predict the Antimicrobial Activity of Cold Atmospheric Plasma-Activated Liquids

arXiv.org Artificial Intelligence

Plasma is defined as the fourth state of matter and non-thermal plasma can be produced at atmospheric pressure under a high electrical field. The strong and broad-spectrum antimicrobial effect of plasma-activated liquids (PALs) is now well known. The proven applicability of machine learning (ML) in the medical field is encouraging for its application in the field of plasma medicine as well. Thus, ML applications on PALs could present a new perspective to better understand the influences of various parameters on their antimicrobial effects. In this paper, comparative supervised ML models are presented by using previously obtained data to qualitatively predict the in vitro antimicrobial activity of PALs. A literature search was performed and data is collected from 33 relevant articles. After the required preprocessing steps, two supervised ML methods, namely classification, and regression are applied to data to obtain microbial inactivation (MI) predictions. For classification, MI is labeled in four categories and for regression, MI is used as a continuous variable. Two different robust cross-validation strategies are conducted for classification and regression models to evaluate the proposed method; repeated stratified k-fold cross-validation and k-fold cross-validation, respectively. We also investigate the effect of different features on models. The results demonstrated that the hyperparameter-optimized Random Forest Classifier (oRFC) and Random Forest Regressor (oRFR) provided better results than other models for the classification and regression, respectively. Finally, the best test accuracy of 82.68% for oRFC and R2 of 0.75 for the oRFR are obtained. ML techniques could contribute to a better understanding of plasma parameters that have a dominant role in the desired antimicrobial effect. Furthermore, such findings may contribute to the definition of a plasma dose in the future.


AI Powered Anti-Cyber Bullying System using Machine Learning Algorithm of Multinomial Naive Bayes and Optimized Linear Support Vector Machine

arXiv.org Artificial Intelligence

Abstract--"Unless and until our society recognizes cyber Hatred, violence, and hostility in modern world can take several form [4],[5],[6],[2], one of which is cyber bullying using modern day technology medium. While the era of internet had brought in tremendous innovation and improvements to our daily activities and overall way of life, it had also opened floodgates for cyber bullying. The impact of social media like Instagram, Facebook, Twitter, WhatsApp, etc. on daily basis cannot be over emphasize as they had greatly influence modern way of communication As useful as social media is, it is a medium for promoting hatred, harassment, racism, etc. which is currently affecting millions of people across the globe. Statistical record from 2019 Cyber bullying Data shows that 95% of teens in the U.S. are online, and the vast majority has access to internet on their mobile device, makes social media platform the most common medium for cyber bullying [11].


An Exploration of How Training Set Composition Bias in Machine Learning Affects Identifying Rare Objects

arXiv.org Artificial Intelligence

This is due to the rapid expansion of computing (Cutri et al., 2013), had many technical challenges and resources and sensor technology in the last four required intensive astronomy expertise, experience, and labor decades that has driven equally rapid expansions in the to overcome (Eisenhardt et al., 2012, for example). A quantity of data to analyze. Astronomy, in particular, necessary first step in that process, though, is to classify has seen a proliferation of large scale imaging and spectroscopic the sources so that we can prioritize which sources might surveys that have billions of sources in them-- be interesting, and which are examples of already known surveys like: the Sloan Digital Sky Survey (SDSS, York sources. Because these sources are rare it is usually easier et al., 2000), the 2-Micron All Sky Survey (2MASS, Skrutskie to use a supervised machine learning algorithm, one that et al., 2006), the Wide-field Infrared Survey Explorer is tuned using sources with known classifications, than it (WISE, Wright et al., 2010), the Gaia satellite's survey is to use an unsupervised one. The reason should be obvious: (Gaia Collaboration et al., 2016), the Panoramic Survey subgroups of the common known source types are Telescope and Rapid Response System (Pan-STARRS) likely to outnumber the rare new ones, meaning a naive surveys (Chambers et al., 2016), the Dark Energy Spectroscopic unsupervised machine learning algorithm could need a lot Instrument (DESI) surveys (Dey et al., 2019), the of complexity before it actually finds the rare class. UKIRT Infrared Deep Sky Surveys (UKIDSS, Lawrence et al., 2007), and the Galaxy Evolution Explorer (GALEX) Supervised learning also has drawbacks when used for surveys (Martin et al., 2005).



Data-driven Models to Anticipate Critical Voltage Events in Power Systems

arXiv.org Artificial Intelligence

This paper explores the effectiveness of data-driven models to predict voltage excursion events in power systems using simple categorical labels. By treating the prediction as a categorical classification task, the workflow is characterized by a low computational and data burden. A proof-of-concept case study on a real portion of the Italian 150 kV sub-transmission network, which hosts a significant amount of wind power generation, demonstrates the general validity of the proposal and offers insight into the strengths and weaknesses of several widely utilized prediction models for this application.


From Multi-label Learning to Cross-Domain Transfer: A Model-Agnostic Approach

arXiv.org Artificial Intelligence

In multi-label learning, a particular case of multi-task learning where a single data point is associated with multiple target labels, it was widely assumed in the literature that, to obtain best accuracy, the dependence among the labels should be explicitly modeled. This premise led to a proliferation of methods offering techniques to learn and predict labels together, for example where the prediction for one label influences predictions for other labels. Even though it is now acknowledged that in many contexts a model of dependence is not required for optimal performance, such models continue to outperform independent models in some of those very contexts, suggesting alternative explanations for their performance beyond label dependence, which the literature is only recently beginning to unravel. Leveraging and extending recent discoveries, we turn the original premise of multi-label learning on its head, and approach the problem of joint-modeling specifically under the absence of any measurable dependence among task labels; for example, when task labels come from separate problem domains. We shift insights from this study towards building an approach for transfer learning that challenges the long-held assumption that transferability of tasks comes from measurements of similarity between the source and target domains or models. This allows us to design and test a method for transfer learning, which is model driven rather than purely data driven, and furthermore it is black box and model-agnostic (any base model class can be considered). We show that essentially we can create task-dependence based on source-model capacity. The results we obtain have important implications and provide clear directions for future work, both in the areas of multi-label and transfer learning.


3D Labeling Tool

arXiv.org Artificial Intelligence

Training and testing supervised object detection models require a large collection of images with ground truth labels. Labels define object classes in the image, as well as their locations, shape, and possibly other information such as pose. The labeling process has proven extremely time consuming, even with the presence of manpower. We introduce a novel labeling tool for 2D images as well as 3D triangular meshes: 3D Labeling Tool (3DLT). This is a standalone, feature-heavy and cross-platform software that does not require installation and can run on Windows, macOS and Linux-based distributions. Instead of labeling the same object on every image separately like current tools, we use depth information to reconstruct a triangular mesh from said images and label the object only once on the aforementioned mesh. We use registration to simplify 3D labeling, outlier detection to improve 2D bounding box calculation and surface reconstruction to expand labeling possibility to large point clouds. Our tool is tested against state of the art methods and it greatly surpasses them in terms of speed while preserving accuracy and ease of use.